An Italian judge has ordered the captain of the doomed cruise ship Costa Concordia be released on house arrest following his first appearance in court today after he allegedly steered the massive ship into rocks and then abandoned the passengers aboard the sinking vessel.

At a press conference, one of the prosecutors would not say what 52-year-old Capt. Francesco Schettino said in his defense during the hearing, but recordings of the radio transmissions between Schettino and the Port Authority revealed today that after Schettino said he abandoned the ship, he claimed he had been thrown from it in the first place.

"We abandoned ship," Schettino says in the recording.

"And with 100 people still on board you abandon ship? [expletive]" a Port Authority official says in response.

The luxury cruise ship was carrying more than 4,000 passengers and crew when it struck rocks Friday evening near Giglio, off the coast of Tuscany. Rescue efforts have been ongoing, but as of Monday night, at least two dozen people remained unaccounted for. At least 11 people were killed in the wreck's aftermath.

Italian prosecutors said the growing evidence Schettino was responsible for the accident, and then failed to protect his passengers. According to a published account by a cook onboard, a full half hour after the incident, Schettino was still asking for his dinner and drinks and reportedly demanded to know where his female companion's dessert was.

Schettino has claimed the ship hit uncharted rocks and that he acted honorably, previously telling reporters he and his crew were the last to leave.

But that's not true according to newly-released audio of port authority radio transmissions to the captain, in which Schettino is repeatedly berated for not returning to the ship.

"Captain, this is an order, now I am in charge. Get back on that ship and coordinate the operations. There are already casualties," the port authority official told Schettino.

"How many?" the captain responded.

"You should tell me that! What do you want to do, go home? Now you get back on that ship and tell us what can be done, how many people are still there and what do they need," the port authority official said.

"OK, OK, I am going," Schettino said.

As a captain for the Costa line since 2006, the year the Concordia was launched, the dark-haired, debonair Schettino was described as a favorite with passengers, especially women.

But if it is true that he and other officers fled the ship, leaving passengers behind, it would be a clear violation of what is regarded as the first law of the sea.

"The captain is the last person to leave the sinking ship," veteran cruise ship commander Capt. William Wright told ABC News. "I find it very hard to understand how any captain under such dire circumstances would elect to leave his vessel."

The Costa line said the captain was wrong to steer so close to the island, although this video from Italian TV is said to show the Concordia, horns blaring one night last August, sailing within a few hundred feet of the island -- a course the Costa line says was authorized and approved in advance.

Prosecutors, however, said Schettino went beyond authorized procedure and was a reckless show-boater.

"You want to screen out the risk takers," marine legal expert John Hickey said. "You want to screen out the hot doggers. You want to screen out people who are not willing to take responsibility."